Okay, this is an interesting design but one with a few issues. I'd say the overall concept is interesting, but there are several areas that need work or need to be expanded on.
First things first, and I admit this is more of a pet peeve than a serious issue, proofreading. There are several misspelled words and the sentence structure is a bit off in places too. Not a serious issue but it's kinda a turn-off and there are a few times where the wording makes it hard to understand your meaning. I'm not trying to put you down, so if you think I'm being a grammar freak just say so and I'll drop it.
Secondly, I'm almost completely lost on the weapon. I have no clue what you mean by "dual split blades" for example, and I'm having trouble figuring out where the flamethrower fits in with all this. Also, what do you picture for a "great-sword"? What I think of is a big two-handed sword that's probably about as tall as Rider, and that really doesn't mesh with a super acrobatic character. The sword would be a massive and unwieldy weight that would make jumping and flipping with it almost impossible. I get that we take a lot of liberties with design, but there still needs to be some common ground between the weapon and the style.
The Semblance is interesting but needs to be expanded on. Does he have to consciously choose to adapt or does it happen automatically? Does it need to be Dust or do naturally occurring elements work too? How long does an adaptation last? Can he cancel it while it's active?
Finally, you really want to use complete sentences for the personality section. Describe them to us you're describing someone you just met to a friend. Choppy blurbs are for dating sites. Remember, we have no idea who this is, so go big describing them.
This is a good start, but it needs work. Keep at it!